1. Field of the Invention
The present invention relates to a cleaning container module and more particularly, to a robust, precise, airtight, electrostatically protective clean container module, which provides a reasonable effect force transferring path when carrying the load, preventing obstruction of precision due to deformation of the container body and ESD protection function during process transportation, and storage.
2. Description of Related Art
In a SMIF (Standard Mechanical Interface) semiconductor factory or foundry, wafer cassettes are commonly used for carrying wafers in horizontal at different elevations. A wafer cassette has a number of support flanges for bearing wafers in horizontal at different elevations. The wafer cassette is set in a clean container module, and then the cover of the clean container module is closed to protect loaded wafers against contaminants such as, moisture in cleanroom and other environment and airborne particles, for further intrabay/interbay process transportation or storage.
FIG. 1 is an exploded view of a prior art clean container module for this purpose. As illustrated, the clean container module comprises a container body 91, a top access board 92, and a wafer cassette 93. The container body 91 has a top mounting aperture 913 in the top panel 911, and a bottom mounting aperture 914 in the bottom panel 912. The wafer cassette 93 is inserted through the bottom mounting aperture 914 into the interior 910 of the container body 91. The top access board 92 is inserted through the top mounting aperture 913 and affixed to the top connecting member 931 of the wafer cassette 93.
The design of the top mounting aperture 913 in the top panel 911 and the bottom mounting aperture 914 in the bottom panel 912 greatly complicates the manufacturing and assembly process of the container body 91, and may obstruct the structural strength of the container body 91. Further, the big top mounting aperture 913 and bottom mounting aperture 914 of the container body 91 affects the airtight arrangement of the interior 910 of the container body 91. Exterior moisture or airborne particles may pass through gaps in the top mounting aperture 913 and bottom mounting aperture 914 of the container body 91 to contaminate storage wafers. In order to eliminate this problem, additional gasket rings or sealing means shall be installed to maintain the interior 910 of the container body 91 in an airtight status. Further, due to many dead corners are created inside the container body 91, it is difficult to clean the clean container and to dry the parts of the clean container module after cleaning.